已有 556 次阅读 2010-5-8 10:56 |个人分类:Stata|系统分类:科研笔记|关键词:SAS, STATA SAS Stata Most operators are the same in Stata as in SAS, but in Stata operators do not have mnemonic equivalents. For example, you have to use the ampersand ( & ) and not the word \ This works: var_a >= 1 & var_b <= 10 where this does not: var_a >= 1 and var_b <= 10 These are the operators that are different in Stata: In SAS operators can be symbols or Symbol Definition mnemonic equivalents such as: & or and For & and many situations in SAS order doesn't | or matter: <= can be: =< and >= can be: => >= greater than or equal to <= less than or equal to == equality (for equality testing) != does not equal ! not ^ power Note: Symbols have to be in the order shown: \>= \=> \ /* this is a comment */ * this is also a comment // this is a comment as well To continue a command /* this is a comment */ * this is also a to the next line (line continuation): /// you can comment ; comment here as well For example: list id state gender age income /// race income date Range of values: if 1 <= var_a <= 10 or: if var_a in(1,2,3,4,5,6,7,8,9,10) or a list of character values: if state in(\ if var_a >= 1 & var_a <= 10 or: if inrange(var_a,1,10) or: if inlist(var_a,1,2,3,4,5,6,7,8,9,10) or a list of string values: if inlist(state,\ Stata has a limit of 10 arguments to inlist() (which includes the string variable) when the arguments are strings. More than one variable can be specified. Referencing multiple variables at a time: Say the following variables are in a data file Referencing multiple variables at a time: var1-var5 in the order shown: var1 var2 var3 age var4 To Stata, this means \variables that are var5 Then you could code them as: positionally between var1 and var5.\Notice that var1--var5 To SAS, this means \there is only one dash ( - ). that are positionally between var1 and var5,\age. Referencing multiple variables at a time: var1-var5 is the same as: var1 var2 var3 var4 var5 no matter the positions of the variables are in the observation. Using a colon selects variables containing the same prefix: var: could represent: var1 var2 var10 variable varying var_1 Referencing multiple variables at a time: var? The question mark ( ? ) is a wild card that represents one character in the variable name. It could be a number, a letter, or an underscore ( _ ). var* The asterisk/star ( * ) is a wild card that represents many characters in the variable name. They could be numbers, letters, or underscores. Thus: var* could represent: var1 var2 var10 variable varying var_1 To save the contents of the results window, start logging to a log file BEFORE you submit commands that you want logged. Open a log file by clicking on the icon in the tool bar that looks like a scroll and a traffic light. A \*.log\file is a simple ASCII text file; a \*.smcl\tags. You can also use the log command: log using \replace Note: The replace option simply tells Stata to overwrite the log file if it already exists. This is helpful when you have to run a do-file over and over again. To save the contents of the Log window and/or Output window, go to that window and click on the menu bar's \\In SAS batch mode these files are automatically generated for you. libname in \data new; set use \You can also in.mySASfile; run; or, starting in SAS 8: data click on the \file\icon and select your new; set \dataset. run; Save the dataset newer to \: libname in \data in.newer; set new; run; save \To overwrite the dataset newer if it already exists: save \You can also click on the \ proc contents; On selected variables: proc describe On selected variables: describe id state contents data = in.newer (keep= id state gender age income gender age income); run; summarize On selected variables: summarize age proc means; On selected variables: proc income If you want variable labels and a proc means; var age income; run; or proc univariate style output try: summarize age univariate; var age income; run; income, detail or: codebook age income proc freq; table var1; run; tabulate var1 or, for just checking out your dataset, try the codebook command. A series of 1-way tables: proc freq; tables A series of 1-way tables: tab1 var1 var2 var1 var2; run; A 2-way table: proc freq; tables var1*var2; A 2-way table: tab2 var1 var2 run; proc print; selected variables in this order: proc print; var id age income; run; On selected variables and a limited range of observations: proc print data = new (firstobs = 1 obs = 20); var id age income; run; list On selected variables in this order: list id age income On selected variables and a limited range of observations: list id age income in 1/20 Create a numeric variable with a default generate var1 = 1234 Note: the default numeric
stata和sas命令对比
